Field of Technology
The embodiments herein relate to an organic light emitting display panel capable of improving luminous efficacy by efficiently extracting light generated in an organic light emitting layer.
Discussion of the Related Art
In recent years, a variety of flat panel display devices having reduced weight and volume, which are drawbacks of cathode ray tubes (CRTs), have been introduced. Examples of flat panel display devices are liquid crystal displays (LCDs), field emission displays (FEDs), plasma display panels (PDPs), and organic electroluminescent displays (ELDs). Among these display devices, an organic electroluminescent display is a self-emitting device operable without a backlight. Owing to excellent characteristics such as slim design, light weight, simple manufacturing process, wide viewing angle, rapid response, and high contrast ratio, the organic electroluminescent display is spotlighted as a next generation flat panel display.
In particular, an organic electroluminescent display device emits light using energy generated by transition of excitons, which are generated when holes injected from an anode and electrons injected from a cathode recombine in a light emitting layer, from an excited state to a ground state. All light beams generated in an organic light emitting layer of such an organic electroluminescent display device cannot reach the outside and most of the light beams are lost by total internal reflection. Since only about ¼ light beams generated in the organic light emitting layer reach the outside, the organic electroluminescent display device has low luminous efficacy.
Thus, there is still a need to develop various methods of improving luminous efficacy by efficiently extracting light generated in the organic light emitting layer.